1. Field of the Invention
This invention relates to processing one-bit digital signals (e.g. one-bit digital audio signals), and to input stages for receiving such signals.
2. Description of the Prior Art
When a one-bit signal is received by digital signal processing apparatus (e.g. from a transmission line such as a coaxial cable) it is common to use a thresholder or slicer to "clean up" the received signal. This is done by the thresholder generating an output at one of two signal levels (to represent the two possible states of the one-bit signal) dependent upon whether the received signal is above or below a threshold level.
However, if the signal on the cable is removed (for example, because the source of the signal is unplugged or powered down), then the thresholder would output a consecutive string of the same value, which in one-bit digital systems represents a very large output signal indeed. In a one-bit digital audio system this could lead to overload of subsequent processing devices.